As individuals age, their movements naturally slow down due to factors such as a slower metabolism, loss of muscle mass, and decreased physical activity over time. New research conducted at the University of Colorado Boulder suggests that older adults may also move slower because it costs them more energy to do so compared to younger adults. This research, recently published in The Journal of Neuroscience, could potentially lead to new diagnostic tools for movement-related disorders like Parkinson’s disease and multiple sclerosis. By analyzing the movement patterns of participants using a robotic arm, researchers found that older adults modified their movements at times to conserve energy, possibly due to decreased muscle efficiency and strength with age.
The study also explored how aging affects the reward circuitry in the brain, as dopamine production decreases with age. Participants were asked to use the robotic arm to reach a target on a screen in order to receive a reward signal. Researchers found that while both young and older adults responded to rewards by moving faster, older adults showed better reaction times, initiating their movements sooner on average. The preservation of reward circuitry in older adults suggests that age has a stronger effect on sensitivity to effort costs rather than sensitivity to rewards. The findings of this study may contribute to the development of new diagnostic tools for movement-related disorders and provide insights into potential interventions to slow or reverse the decline in movement speed associated with aging.
Dr. Alaa A. Ahmed, the senior author of the study, emphasized the importance of understanding the underlying causes of movement slowing with aging and neurological disorders. Movement speed can significantly impact one’s quality of life, restricting physical and social activities. By identifying the factors contributing to movement slowing, researchers hope to develop interventions that can help mitigate this decline and improve overall neurological health. Movement speed may serve as a valuable biomarker for neurological health, offering a noninvasive and easily accessible measure to track changes in movement patterns over time.
Neurologist Clifford Segil, DO, from Providence Saint John’s Health Center, agrees with the study’s emphasis on maintaining physical activity as individuals age. Encouraging elderly patients to exercise can have multiple health benefits, despite the increased energy cost required to perform the same activities as younger individuals. He suggests that further research incorporating EEG monitoring to assess brain activity during movement tasks would provide valuable insights into how the aging brain adapts to challenges related to movement. This comprehensive approach could help support the claims made in the study and guide interventions for aging patients experiencing movement-related challenges.
Ryan Glatt, a brain health coach at Pacific Neuroscience Institute, acknowledges the intriguing hypothesis put forward by the study linking slower movements in older adults to energy conservation and reward processing. However, he highlights the importance of correlating observed behavior with underlying neural mechanisms through direct neurological evidence. Future research should aim to strengthen the findings by directly linking behavioral data with neurophysiological evidence, utilizing longitudinal studies, diverse population samples, and larger sample sizes. Replicating the study under varying conditions will ensure the robustness and generalizability of the initial results, shedding light on the mechanisms underlying age-related changes in movement speed and brain function.
